Reply to: Adding a super-simple electrical circuit to garage

[xoggoth]

My 2 sheds and greenhouse have been wired up for years to an extension socket with no problems at all. I have made sure that the wire is securely buried in a pvc pipe underneath paving slabs though, sticking it where you can accidentally put your garden fork through it is not a good idea.

[gingerjedi]

My garage already had a mains feed from the main consumer unit but I wanted to add lighting, I read up on regs/ best practice and the advise said it was fine to run lighting off a mains spur but you must put a fuse between the socket spur and the light switch.

In short you only need one feed for both mains and lighting if you do it this way.

[Lockhouse]

Also it lets you say "if a job's worth doing, it's worth doing well."

WCS

I could have just run spurs but I wanted to have lots of points so actually a ring main is much tidier. Plus there's the satisfaction of doing it properly. It's been running nearly 18 months and the only time it's ever tripped was when the lathe developed a fault. i.e. when it was supposed to.

[Contreras]

Lockhouse what is the benefit of setting up a ring for the sockets rather than having it just a spur?

The garage consumer unit Lockhouse linked to is 16A + 6A MCBs so would be OK to have the sockets and lighting circuits on spurs respectively. A ring for the sockets would in theory mean you'd be OK with a 32A MCB in the garage consumer unit but in practice still limited by the upstream protection device. Also it lets you say "if a job's worth doing, it's worth doing well."

[darrylmg]

If it's just a spur you need a lower rated fuse in the fused socket, so you don't keep tripping the ring main you're spuring from if you've got a dodgy socket in the garage.
For lighting I thought it was 16amp supply and only 32 for power.
Then there's the different thickness cabling used for lighting than sockets.

A seperate ring in the garage is great if you want to disable the lighting ring but leave power sockets working or vice versa.
Plus as mentioned, you don't loose your house electrics if there's an issue.

You could do the lot properly yourself for £100. But you should really get it done by an electrician for the insurance sake.

[d000hg]

Lockhouse what is the benefit of setting up a ring for the sockets rather than having it just a spur?

[DimPrawn]

Have you asked Bob?

[Lockhouse]

I wired my home workshop powering a lathe and milling machine (both 240v) with one of these. I used an existing spur from the fusebox which had gone to an old shed that I'd demolished. I did a mini ring main for the plug sockets and a simple double spur for the lights.

This was it halfway through though.


Before anyone goes into one, I did have it checked out by a qualified electrician afterwards and all he said was how did I get so much cable down 1/2" conduit....

All I will say is make sure it's properly earthed. I put studs directly into the concrete foundation.

[Contreras]

An extension lead doing the same job doesn't... it's 15m which is shorter than many people use to power a hedge trimmer across their garden

Yes quite. But an extension lead is not a fixed installation and therefore not covered by the (same) regs.

TBH, my initial thoughts on your OP were why not just rig something up with an extension lead protected by an RCD.

[d000hg]

And depending on distance it may also need a separate earth rod whacked into the ground at the garage end.

An extension lead doing the same job doesn't... it's 15m which is shorter than many people use to power a hedge trimmer across their garden

[Contreras]

As HyperD intimates you really need a dedicated spur and consumer unit in the garage, anything else is a false economy

And depending on distance it may also need a separate earth rod whacked into the ground at the garage end.

[SimonMac]

As HyperD intimates you really need a dedicated spur and consumer unit in the garage, anything else is a false economy

[hyperD]

dooogh, GF#1 has a rental which has a well shielded spur from one of her ring mains (no snorting here please) to her garage that splits into a junction box which lights up a fluorescent tube and two sockets - prob 13 amp, so she can run her freezer and tumble drier.

It looks a little dodgy (as in the splice from her house is stretched over the roof of her garage) but it seems to work.

Purely from observation, don't know if that helps or not.

Might be worth discussing with an electrician as I don't know what HSE paraphernalia would potentially void any current insurances/certificates.

[d000hg]

Good point, but mainly just lighting and maybe a TV/HiFi rather than a workshop. Quite likely things like tools will be used, but nothing I wouldn't currently plug into a regular mains socket - hand-drill, jigsaw, hoover, etc. Nothing industrial/heavy duty.

[Sockpuppet]

What are you powering in there i.e. rating of tool etc. 13amp isn't a great deal into a garage.